Concentrating apparatus



May 22, 1951 J. A. cRoss CONCENTRATING APPARATUS 6 Sheets-Sheet l Filed Sept. 14, 1944 L1- ---lill May 22, 1951 J. A. CROSS CONCENTRATING APPARATUS 6 Sheets-Sheet 2 Filed Sept. 14, 1944 faQ/[ey May 22 1951 J. A. cRoss 2,554,138

CONCENTRATING APPARATUS Filed Sept. 14, 1944 6 Sheets-Sheet 3 May 22, 1951 J. A. CROSS CONCENTRATING APPARATUS 6 Sheets-Sheet 4 Filed Sept. 14, 1944 E fg/ May 22, 1951 J. A. cRoss 2,554,138

CONCENTRATING APPARATUS Filed Sept. 14, 1944 6 Sheets-Sheet 5 /0 F579 -ky? k# May 22, 1951 J. A. @Ross 2,554,138

CONCENTRATING APPARATUS Filed Sept. 14', 1944 6 Sheets-Sheet 6 Pz ./f. l ff( E i i f6@ f 0; wf i *Py/V i /f Z8 yg p7@ Patented May 22, 1951 ATENT OFFICE CONCENTRATING APPARATUS Joseph A. Cross, Westerville, Ohio, assignor to Mojonnier Bros. Co., a corporation of Illinois Application September 14, 1944, Serial No. 554,015

7 Claims.

The present invention relates to concentrating apparatus for use in preparing various kinds of edible foods such as the various condensed milk products, concentrated citrus and other fruit juices, soups and the like.

One object of the invention is to provide novel apparatus of the character mentioned, which shall be capable of long periods of continuous operation. In this connection it is also desirable that the apparatus be useful in handling liquids of great viscosity and to handle all the products, for which it is designed, with rapidity.

Another object, looking to the production of sanitary apparatus, includes the provision of a removable cover on the food side of the heat exchanger, which may be readily secured in place for operation, and as readily removed for cleaning. The use of an inflatable tubular gasket contributes to this end.

Another object is to provide apparatus in which the outlet from the separating chamber may be connected with the inlet manifold of the heat exchanger for recirculation therethrough. In this way the product, which may not have been sufciently concentrated by a single passage through the equipment, may be recirculated until the desired degree of concentration is obtained.

Another object is to provide novel apparatus of the class mentioned in which the heating and condensing elements are, for the most part, quite separate. Thus, they may be easily inspected and cleaned. All of this contributes to good sanitation.

Another obiect is to provide great flexibility of design as between the heating surfaces and the collecting or separating chamber. This is made possible by keeping these two elements apart. Thus, a very large heating surface can be provided with a relatively small condensing means, so the product will be in transit a very short time, and by its rapid travel and is short time in contact with the heat, the natural characteristics of the product remain more nearly like the original.

Another object is to provide apparatus of the class described having heating elements arranged for progressive evaporation of the liquid.

These and various other obiects and advantages will be more fully set forth in the following description taken in connection with the accompanying drawings, which illustrate a preferred embodiment of the invention. .The scope of the invention will be particularly pointed out in the appended claims.

In said drawings- Fig. 1 is a side elevation of apparatus constructed and arranged in accordance with the present invention;

Fig. 2 is a front elevation of the same aplparatus;

Fig. 3 is a, rear view of the lower portion of said apparatus;

Fig. 4 is a plan view of the apparatus;

Fig. 5 is a face View of the heating element employed in the apparatus;

Fig. 6 is a side elevation of the heating element, the upper portion being shown in vertical section taken on a plane indicated by the line 6 6 of Fig. 5 and other portions being broken away to show more clearly the connections for the heat exchange medium;

Fig. 'l is a bottom plan view of the heating element, a portion being shown in section to indicate more clearly the tubular arrangement, the section being taken on a plane indicated by the line 1 1 of Fig. 5;

Fig. 8 is a transverse section taken through a porti-on of the heating element with the closure in place and illustrating the way in which the expansible gasket acts, the plane of section being indicated by the line 8 8 of Fig. 1;

Fig. 9 is an elevation of the upper chamber or manifold connected with the heating element, a portion of the same being shown in vertical section taken on a plane indicated by the line 9 9 of Fig. 10;

Fig. 10 is a horizontal view showing the greater portion of the upper manifold in section, the plane of section being indicated by the line I 0 1 0 Aof Fig. 9, and also the barriers in the bottom of said manifold being broken away to clearly show the openings therethrough;

Fig. 11 is a transverse section of the heat eX- changer taken in part on the plane indicated by the line H II of Fig. l;

Fig. 12 is a similar'section viewed in the opposite direction to Fig. 11, taken on a plane indicated by the line |2 l2 of Fig. 1;

Fig. 13 is a detail view of the clamping arrangement for holding the closure in place, the direction of the view being indicated by the line 13 l3 of Fig. 9 and accompanying arrows; and

Fig. 14 is a detail view o-f the lower edge of the closure and its expansible gasket showing the valve stern, the plane of section being indicated by the line lll-I4 of Fig. 1.

Throughout these views, like characters refer to like parts.

Referring to said drawings, A designates the heat exchanger portion of the apparatus, and

B the condensing and separating portion. The latter portion consists o-f a vacuum chamber having means for condensing the vapors in the top and a space for collecting the liquids in the bottom. The heat exchanger portion A comprises vertical tubular elements C which extend between an intake manifold D and a relatively large horizontal cylindrical chamber E which serves as the outlet manifold. The liquid to be treated is fed through a pipe F into the outlet manifold in a direction preferably parallel to that taken by the heated liquid discharged from the upper ends of the tubular elements C. The liquid fed through the passage F strikes the cylindrical wall of the chamber E and rotates in a counterclockwise direction as viewed in Fig. l1. It passes down through an outlet passage G, sometimes called a downcomer, and from that passage is fed into the lower manifold D. In this way the liquid travels around within the chamber E and down through the downcomers G, of which there are in this instance three, and into the lower portion of the heating elements, which heat the liquid and cause it to rise and enter the same chamber E with considerable force, also with a rotary counterclockwise direction, as viewed in Fig. 1'1. The chamber E is connected by a. passage I-I with the lower part of the chamber B. In chamber E as the heated liquid is rotated, the heavier particles tend to move to the periphery, and the lighter particles to the center. From this point they pass through the passage H into the condensing and separating chamber B. The chamber B is provided with a suction connection J so that the entire chamber, both upper and lower portions, is subject to vacuum. This vacuum acts upon the rising Vapor to withdraw it through the upper portion of the chamber B and allows the-more or less concentrated liquid which is heavier to collect in the lower portion of the same chamber B. The vacuum in the chamber B also vacuumizes the chamber E which acts as the upper outlet manifold E. The liquid in its rotation around within the chamber E is divided by partitions K and deflectors L. The force given to the liquid as it is heated and discharged by the heating elements C, when coupled with the suction applied by the vacuum at the right end of chamber E, as viewed in Fig. 1, separates the lighter particles from the heavier and allows the latter to pass progressively from section to section, through suitable holes in the barrier K each time being recycled to its section by its downcomer. This action may be repeated as many times as may seem desirable by multiplying the downcomers G and barriers K. In the present instance, there are three downcomers G and three sets of partitions K and deflectors L. Thus there are three evaporator units. In an embodiment actually tried out, with three downcomers and other parts as shown, the eiect of the evaporation per square foot was 40 pounds per hour in the first or left-hand section, as viewed in Fig. 9, 30 pounds per hour in the second section and 20 pounds per hour in the third.

The chamber B may be of the ordinary vacuum pan type of construction, but not having the heating coils located within the chamber B. It however receives its supply of heated liquid in a tangential direction over a considerable portion of its cylindrical wall, as will be explained later. In the present instance, the vapors are condensed by a stream of water, as usual and as we shall also see later.

With this general view of the apparatus and its way of acting, we may now proceed to a detailed consideration of the same.

The heat exchanger elements C (shown generally in the drawings but more particularly in Figs. 5 to 8, inclusive) are provided in the specific instance by bending a sheet of metal back and forth in corrugations as illustrated, to provide a number of tubes for the heating medium and a number of similar tubes 2| for conveying the liquid to be treated. The plate 22 cooperates with the bent sheet 23 to complete the tubes 2B. The plate 22 is provided at its ends with flanges 24 which in turn are extended outward at 25 and are provided with a terminal flange 26. This boxlike structure receives the closure 21 which, in the present instance (see Figs. 8, 9, 10, etc), takes the form of a door provided with a peripheral channel 28, which door with its channel is adapted to t within the flange 26. The inner wall of the door is provided with a plate 2 9, which also ts against the bent sheet 23 to form the tubes 2| which constitute tubes for carrying the liquid. to be treated, or other liquid food. It will be seen that the tubes 28 are permanent and, when once fabricated, cannot be opened up. On the contrary, the tubes 2|, which are closed with the plate 29, upon the cover 21, may have one side or wall placed, or removed, according to Whether the door is in closed or open position. Thus, the tubes 20 and 2| constitute heating and treating passages, the latter of which discharge 'tangentially into the upper manifold chamber E.

When the food carrying tubes 2|, made up of the corrugated plate 23 and the closing plate 29, are to be cleaned, it is only necessary to remove the plate 29. This is done by swinging back the cover 21. Then all the walls of the tubes 2| may be easily cleaned.

The covering door 21 (see Fig. 1 etc.) is pro vided with a pair of hinges 32 by which it is swung from open to closed position, or vice versal The hinge member 33 in each case has at its' end a slot into which fits a swing bolt 34 carry-f ing a thumb nut 34a. These parts are shown in detail in Fig. 13 and it will be obvious how the same may be operated. Behind the hinge members 33, reinforcing blocks 35 may be secured to the member 33 or the plate 29 or both. Likewise, any number of hinges may be employed according to the judgment of the designer.

In lieu 0f hinges 32, the closure may be modied so as to seat it the same as any cover provided with swing bolts 34. Thus, each end of the transverse member 33 may be slotted and swing bolts 34 used. Such alteration will occur to worker in this art in the course of their calling.

The tubes 2| open into three intake sections or chambers 36, 31, 33 (see Fig. 5), between which are located the partitions 39 and 40. The partitions 39 extend through the entire height of the tube chest, as shown in Fig. 5, hence provide not only the three intake chambers 36, 31 and 38 but three corresponding outlet chambers for the liquid product as it emerges from the upper ends of the tubes 2| into the vapor separator E. Thus, liquid within the sections cannot be passed from one sectional chamber to the next without rst going through the tubes 2|. These sectional chambers are at the inlet ends of the tubes and constitute the inlet manifold D of the heater. Section 38 is provided with an external connection 4| for providing a recirculating path, as will be noted hereinafter.

Suitable nipples` 42, 43, 44, provide for connecting the downcomers G. This provides .for the incoming liquid and comprises the description of the inlet manifold.

The outlet manifold (see Figs. 9, 10,'for details) takes the form of a relatively large horizontal cylindrical chamber E which is closed at one end by a dish-shaped wall having a manhole 46 and a glass covered peephole 4l.` For securing the manhole 46 in place, any suitable retaining means 48 may be employed such as swing bolts provided with suitable thumb nuts. An opening 49 is also provided for the insertion of a light to View the interior of the chamber during operation. The opposite end of the chamber is partially closed by a similar dishshaped end wall 50 which is provided with a vertical opening 5| which constitutes an outlet opening for the chamber or upper manifold E.

It will be noted that this outlet manifold E projects outward from one side of the upright chamber B and has one end open so as to place its interior in communication with the interior of said chamber. As it is built in with the other elements of the heat exchanger, it makes the latter very accessible and easy to clean. It also provides for ease in manufacture. The heat exchanger may be made almost any size, quite irrespective of the size of the chamber B.

The connecting passage H (see Figs. 9, l0,

etc.), which connects the horizontal chamber E and the lower portion of the upright chamber B, is provided by a duct extending from the opening 5l to and into the chamber B and comprising side walls 52 and 53, a top 54 and a bottom 55. The latter are upwardly and downwardly crowned so as to resist any tendency to buckle. The bottom 55 extends only between the chamber A and B. The sides and top extend within the chamber B, as clearly shown in Fig. 4. Therefore, the contents of the passage are discharged in a tangential direction into chamber B. The wall 53 has an extension 56 which is curved as shown in Fig. 10, and catches the liquid as it comes around within the .chamber E to direct it out along the curved path formed by the walls 52, 53, extending to a point well on in the chamber B, as clearly shown in Fig. 4, the side wall 52 merging into the cylindrical wall of the chamber B. The opening 5l., with which the passage H cooperates, extends upward from the bottom of the passage, as clearly illustrated, and is relatively narrow. The extension 56, which lies at the entrance to the discharge passage, is in fact a deflector which extends into the manifold E in a direction to guide the liquid or fluid being treated into the discharge passage. The greatest dimension of the defiector 5t is vertical, hence it is called a vertical deflector.

The connection between the outlet manifold E and the intake manifold D, designated generally as G (see Figs. 1, 9, l0, etc.), comprises three downcomer tubes or pipes 59, Bil, 6l, which lead from funnel-shaped openings 62, 63, 64, in the bottom/of the chamber E, downto transverse pipes 65, 65, 6l, which are respectively connected at their forward ends with the vnipples 42, 43, 44 of the sections 36, 3l, 3&3 of the intake manifold D. Thus the downcomers G convey the liquid from the outlet manifold E to the inlet manifold D, section by section. `1in other words, the upper manifold E has outlet passages which lead from openings in its bottom to the lower manifold D where the conveyed liquid begins its upward climb through the treating tubes loer.

6 l 2i under the action of the parallel heating tubes 20, all as indicated by the arrows in Fig. 11.

The intake pipe F (see Figs. 9, 10, 12, etc.), through which the liquid to be treated is Supplied to the horizontal chamber E, lies preferably parallel to the elements of the heat exchanger so that, upon delivery of its contents to the interior of the chamber, the same may be carried around the interior of the cylindrical wall in the same direction as the heated liquid that is discharged from the upper ends of the heat exchanger. It might be introduced through the supply passage set in some other position than that illustrated. It is only necessary that the liquid passing into the chamber be injected so as to strike the cylindrical wall in the same way and to give the same direction of swirl as that issuing from the upper ends of the tubular passages. This intake pipe F has a regulating valve 'l5 therein. The upper end of the pipe is secured to the cylindrical wall of the chamber E, well toward one end of the same, as shown.

Obviously, the liquid delivered by the supply pipe F, set as shown, will rotate within the chamber E throughout the greater portion of its circumference before encountering the funnelshaped outlet 52 through which the greater portion of it passes into the downcomer 59 and is delivered to the first section 36 of the intake manifold D. After being heated in the first section of pipes, it is discharged therefrom into the outlet manifold E, and after again making repeated circuits of the circumference, during which still more of the heated vapors are carried off, it passes through openings in the barrier K into the second section and its downcomer E0 and is delivered to the second section 31 of the intake manifold D, where it is fed into the second section of heating pipes. A like operation occurs for the third section, the third downcomer 6l and section 33 playing their part. All of this operation will be explained more fully hereinafter.

At this point, it may be noted that the stream which is sucked through the passage l-I into the lower portion HIB of the chamber B comprises the heavier concentrates and lighter gases and vapors. The heavier concentrates flow over the lower portion of the passage while the lighter substances are more elevated. As the stream enters the chamber B it necessarily expands somewhat due to the larger capacity of the cham- It also enters the chamber with a swirling motion. This motion tends to separate the heavier concentrates which are collected in the bottom of the chamber, from the lighter gases and vapors which are drawn upward into the upper portion where they are subjected to the usual jet condenser action.

Where the preliminary rotation is not considered of sufficient importance, the incoming pipe connection F may be replaced by one which connects directly with the lower manifold of the heat exchanger. Then the rst movement of the liquid would be up through the first section of heat exchanger pipes and the pipe connection F would be omitted.

Turning to the supply of the heating medium which for the present may be assumed to be steam, it will be noted that the same is supplied vto a steam manifold lli. This manifold is formed upon one side of the plate 22 of the tubes 2|. As indicated in Fig. 5, the steam manifold 'i6 is provided with a slot ll. This opening or slot 11 extends completely across the heat exchanger.

A short nipple 8|] is connected directly to the manifold 16. In this way, steam is admitted to all the heating tubes 20. These tubes are closed oif at their opposite ends, as indicated by scalloped plates 8| and 82. The projecting portions of the plate 1| cover and close the upper ends of the tubes and leave the tubes 2| open for the passage of the liquid. The projecting portions of the plate 82 in like manner close the tubes 20 at their lower ends and leave the tubes 2| open for the passage of the liquid. The steam outlet through which the condensate flows is similarly provided by an outlet manifold 83 having a nipple 84. The manifold 83 similarly extends throughout the width of the heat exchanger, as illustrated more particularly in Fig. 5. There the opening 85 is in the form of a slot extending from one end of the manifold to the other. Thus, steam is admitted and passed through the heating pipes 29 in heat exchange relation to the treating pipes 2 The steam on its way to the manifold 16 (see Figs. 2 and 3) passes through a strainer 8S, a globe valve 8l, a pressure reducer 98, and a throttle valve 89. Similarly, the condensate passing from the exchanger passes by way of outlet 84 and outlet pipe 92 to a steam trap 93, which suitably discharges through a pipe 95 into a sewer connection or directly upon the floor, as

shown. The usual steam connection with the f pressure reducer 8B is provided by the small pipe 90.

It will be noted that the upper portions of the tubes, which are adapted to contain the heat exchange medium, are connected to a vent manifold 96. A vent pipe 91 connects this manifold directly to the atmosphere at a point considerably below the vent manifold. This vent serves to carry off air, non-condensible gases and the like. The manifold 9S and vent pipe 9'! are shown more particularly in Figs. 5 and 6.

The interior of the outlet manifold chamber E is divided into three units or sections by the partitions K (See Figs. 9, l0 and 11). These partitions extend preferably throughout one-half of the circumference of the chamber and are associater respectively with the deilectors L. The partitions or barriers K are provided with a number of transverse openings 93, 99, |09, there being preferably three employed in the equip- 'ment shown. Likewise, the deilectors L are provided with transverse flanges I9I, |92, |93. The action of these perforated barriers and the flanged deectors is to keep the heavier ingredients near the periphery of the chamber and in the sections to which they belong, as they rotate and are acted upon by the vacuum of the condensing and separating chamber B. It will be seen that as the liquid is forced upward and around, the heavier particles will tend to cling to the circular wall of the chamber E more tenaciously than the vapor particles which are carried away by the suction constantly applied. Thus the concentrate is held by the barriers K and slowed down in its travel toward the outflow passage H, finally reaching the bottom of the chamber B where it is collected and withdrawn.

Thus, in operation, the liquid which passes into the intake manifold D (for details see Figs. 6 and 11), flows upward through the treating tubes 2| and out into the outlet manifold E. The steam ows downward and upward into and through the heating tubes 2|), passing inward at the manifold 'I6 while the condensate is discharged at the heating medium outlet manifold 83.

The barriers K (for details see Figs. 9, 10, and 11) retard the flow of the concentrates. The first two retard its flow into the downcomers 6D and 6|, respectively, and the third into the final outflow passage H. Of the three barriers K, two are in alignment with the partitions 39 and 4U respectively, and the third being at the far side of the heat exchanger from the supply passage F, and adjacent to the outflow passage H, effectively retards the flow of the liquid being treated. The deectors L in the top of the manifold E are three in number arranged in line with the barriers K.

Thus, to present the steps of the operation more in detail, the fresh or raw liquid to be treated is continuously supplied through the supply pipe F (see Fig. l2) into the rst section of the hori- Zontal outlet chamber or manifold E and is directed by the curved wall thereof (see Fig. 11) in the same direction as the heated vapor and liquid emerging from the treating tubes 2| into the same chamber. Liquid passing down by gravity through the first downcomer 59 into the rst intake chamber 36 (see Fig. 5) of the intake manifold D obtains access to the rst section of treating tubes 2| (See Fig. 10) and is rapidly heated through the associated heating tubes 20 of the firstunit. The heated liquid is forced upward through the tubes 2| by the applied heat and emerges from their upper ends in a violent centrifugal swirl within the rst section of the outlet chamber E. This swirling mass emerges as hot vapor and more or less concentrated liquid. As it swirls around, the vapor passes out and more or less concentrated liquid passes down through the same downcomer 59 and is recirculated. In the recirculation of this first unit, the downcomer 59, the intake chamber 36, the first section of treating tubes 2|, and the first section of the outlet chamber E constitute the recirculating or cyclic path of the first effect or unit. As the liquid travels over this circuitous path, it is kept more or less within the limits of the first unit of the outlet manifold E by the deflector L and barrier K of the first section, namely, those having the flange lill and the apertures 98 (see Fig. 10). The heavier concentrate and the lighter vapor are thus separated, the vapor responding to the drawing force of the vacuum which sucks the vapor out through the circular orice or openingprovided by the meeting deector L of the first section (having the flange IGI) and the aligned barrier K (having the openings 98). The vapor ultimately passes out through duct H. The meeting deflector L and barrier K, in addition to forming the orifice, provide a marginal wall which holds the more or less concentrated liquid which travels near the periphery of the chamber E, as the mass swirls under centrifugal force. Thus the particular deflector L and barrier K constitute partition means near the outgoing end of the first unit for baffling the entrainment of droplets of the liquid along with the vapor. This particular deflector L and barrier K serve to guide the partially concentrated liquid within the first unit. This liquid, including the centrifugally separated droplets, is thus guided down to the downcomer pipe 59 and the other elements of the recirculating path and is given a number of recirculations according to the relation between quantity of liquid supplied and the quantity of partially concentrated liquid withdrawn. Ordinarily, the quantity of the partially concentrated liquid withdrawn is but a small fraction of the total amount of liquid being reciroulated. The point at which this withdrawal taires plage i in the lower portion of theputlet chamber E where vthe three openingsf "f (see Figs. '9, 10 and l1) are located. 'Ihese'o'peningsf4 y9 8 formthe passageway into the neXt evaporator Upon entering the second unit o f the manifold E, namely, that bounded on both sdesby the deectors L and barriers K (the deflectors having the flanges lli! andV |532 and the barriers' having the openings '3 and 99) (see Figs.v 9 and 10) ,the partially concentrated liquid is subjected'tof fur; ther exaporation, but this timefi't has a higher starting temperature. It is thus furtherconoenipated'.'r Here the cyclic path include sthe seo fd downcom'er 6 0, the intake chamber 3l, the second group of liquid treating tubes?! (see Figllfarid the central unit ofthe outlet 'chamber The partially concentrated liquid travels over this crsuitdus path a number pf times aPSCOntingr ously discharges itslfur'ther concentrated'pro'duct through vopenings se of its barrier K.

In the 4third unit, the operation isV again repeated, this" time starting with a still merecencentrated liquid. The downcorner el,` the section or chamber Sii of the intake manifoldD, the group associated treating tubes 2i of the element C, the delector L having the ilange I3, and the barrier K having the openings lll here alli `c orne into play in a similar manner. The @por isv again "discharged, The liquid in prac'- tically its .nal state of concentration is delivered the discharge duct H and by it to the chamber B. n If it should require further treatmentbecause thedegree of concentration is insufficient, the liduidn1ay be again passed through the vthird evaporating section, as will be explained hereinf 'and 'when Considering the piping. 'I hevupright cylindricalchamb'er B (see Figs. 1 and?) has an upper portion and a lowerportion." .The lower portion it@ serves as a col-lecting portion for Vthe concentrate. The bottom lil] the chamber is inclined downwardly toa low pont at its front. There a striking cup valve'vl 03 ated. 'when a sample of the condensateis to be'withdraWl, a ycup is pressed upward against suitably gasketed plate on thelowerend'of the valve. `This makes `a tight connection between ,tiret/wo. N'Ihen by turning the valve to open position,l l the cup is lled, or partially filled, as. de;- sired. Then the valve is shut off andthe filled forl partially iilled oup removed. 'Iiicconteiits 'may then be tested for viscosity or otherwise, ,as may be desired. For the purpose of inspecting the' concentrate within the lowerportion tilt of the chamber B, the latter is yprovided lwith peepf holes |09 and i m.

` The vapor is drawn into the chamber yBby the vacuum pump lli, connected through pipe [lf2 Avi/"ith A.tliie vacuumoutlet J. A check `valve l L8 theoutgoing side Aof the pumpassistsv in` main'- taining the vacuum. the heated drawn into the chamber B, it is cooledand condensed by coming into contact vwitha-.s upr 15 r o f cold Awater coming through pipe H3 into .a suite able spray device lift, which `is sprayed about within the chamber B. The spray device H4 vis suitably adjusted by a .hand-.wheelltl The non condensible gases and the like pass out through pipe connection l l-S. As the spray occurs infthe upper portion oi `the chamber B, it `encounters the `gases'"which pass upward `within Vthe vchamben 'Ihef water travels downward in the `Or-ni 'of 'streams orsheets and has a divergent course-by reason of theoutwardlyextending baiiies i l1 with i rit` e` zrw /c; ning inwardly extending baffles H9. In this way theY gases and vapors are thoroughly mixed Within the upper portion of the chamber and vthe water is drawn off through the pump connectionJ. It twill be noted that 'the interior of the horizontal chamber E is subjectedto the eiih'austingl effect of the suction means, aswell as the interior of the main chamber 'BL fact, the chamber B constitutes av vacuum chamber vwhich is connected to the discharge'passage eX#- tending from the horizontal chamber E and serves to withdraw' the partially treated Iiuid thereirom and further treat the same by subjecting it to the condensing` operation which takes placein the tcp of the chamber B.l Thecanopy i223 located atr the upper end of the tube 'I 2` i'S held in place by a plurality of Supports 12| suitably welded to the canopy and the tube. The water travels down :and lcollects in the trough i22 surrounding the tube and is then drawnoff by ,the Vacuum pipe J which is' locatedat that level; on them-,her hand; the' vapors' pass out through the'upper end of the pipe 'or tube E20 and then are directed downward to theviciriity of the trough E22 where they again rise in bonftactwith the bailies HT and l i9, Iand iso pass out through the connection lli-ii provided for their escape. i

For the purpose of inspection, the upper end of the chamber B is provided with a light opening' 5215 intdwhich a lamp fixture may be passed and properly secured. Likewise, the wall of the chamber ladjacent to this' point is providedwith a manhole' t2 il which may be securedin place by "fg bolts lH26 provided' with securing nuts, as iscommon practice. The manhole cover'is pro# vided lwith a peephole 82B through which' the interior may be viewed. A second peephole [29 is proyided at a point opposite the outlet `J. A coupling i3d is provided for a water thermometer. similar oonnection I3! is provided for the purpose of breaking the vacuum within the chamber B. A further manhole 32 is located just below theconnection J and is inclinedfa's shown'so as' to Vprovide for access to the interior ofthe chamber. rihe cover of this manhole may be secured 'inplace as before by suitable swing bolts ifi having'4 thumb nuts. The-center of the manhole cover is provided with a peephole 435 through which the interior maybe inspected. A coupling for a vacuum'gauge is provided at |33, also steps 'IST by which an attendant may climb up' on the chamber."A thermometer connection lE is 'also provided near the Vbottom of the chamber B1 adjfacent'to its outlet. f Alhe heatA exchanger A isl suitably mounted upon legs E38, vwhile the upright cylinder'B is similarly mounted upon legs T39. A platform l il() extends ,outward` from .the side or" the .upright chamber B. and is reached by a night of stairs 15J The platform ite is supported bythe stairs and a ,les 52. A suitable railing 53 isalSO om: vided Turning now to the piping (see Figs. l to 4 inclusive), will ibe see'n'that the concentrates, having tri neeessarywisepsity ruegree'f [c fc`in` centration`, are 'withfdr'awny from the bottoni vc`i f tlle e chamber B `through a valve controlled outjlet id21 Theyalve M3 controls this'outlet which extends' through pipe i"i' and Dpeifi to the itakesideoi'the 'pump ifif From theoutlt ordelivery side of the saine Dump,'tlie connection collecting device. The continuity of operation of the pipe |48 is controlled by a valve |49 and a check valve |50. Continuing on beyond the pipe |41, in line with it, is a pipe |54 which is controlled by a valve |55. The pipe |54 is connected by an inclined pipe |56 with the third or last section 38 of the heat exchanger. This pipe |56 thus constitutes a valve controlled passage between the lower manifold D and the delivery side of the pump |21. The valve |55, when closed, prevents any ow through the pipe |56. An additional path from the lower manifold D to the intake side of the pump |21 includes pipes |51, |58 and |59. This additional path has its continuity controlled by a valve I I. With valves |5| and |55 closed, the concentrate travels over a path extending from chamber B through elements |42, |43, |44, |45, |21, |46, |41, |48, |49 and l|50 to the point of discharge. The check valve |50 serves to retain the head upon the pump |21 and so maintains the vacuum.

When, in the operation of the system (see Figs. 1 to 4 inclusive), the concentrate shows insucient viscosity, that is to say, insuicient concentration, it becomes necessary to recirculate it. Accordingly, by closing valves |5| and |49 and opening valves |43 and |55, it is possible to circulate the substance over a path which may be traced from the chamber B down through pipes |42, |44, |45, pump |21, pipes |46, |41, |54, |56, back to the third section 38 of the exchange heater, namely, through connection 4|, whereupon it will rise in the heater and pass out at the upper end and proceed, as previously, back to the lower portion |06 of the chamber B. By maintaining this circuit, it is possible to recirculate the liquid until it reaches the required viscosity or degree of concentration as determined by tests.

If this is the end of the run, then the system must be drained, and to do this it is necessary to close valve |55 and open valves |43, |49 and |5|. Thereupon an open pipe connection is provided between the inlet manifold D of the heat exchanger to the pump |21 by way of pipes |51, |58 and |59. Thus, a valve controlled passage is provided from the lower manifold D to the intake side of the pump |21. Then the whole system can be thoroughly drained by the pump |21.

In order to maintain a tight connection bei tween the cover 21 and the fixed element of the heat exchanger, I provide a tubular gasket |60. This takes the form of a pneumatic tube which extends all the way around the cover and lies within the channel 28. In assembling the tube within the channel 28, it is necessary to pass the valve stem |6| through a suitable opening |62 made in a portion of the channel, preferably as shown. When the stem and tube are properly assembled, the tube may be expanded by blowing air into its interior and thus forcing it out into contact with the flange 26 upon the fixed portion of the exchanger. For this purpose, the

' stem |6| is provided with a valve such as is ordi- 12 cover 21 is easily removed upon deating the gasket.

Except where otherwise indicated, the various parts are composed of metal and in places Where the liquid to be treated engages the metal, it preferably is composed of stainless steel. Thus, the wavy sheet 23 and the engaging cover 21, which make up the treating tubes 2 I, is composed of stainless steel. Again, the two pumps, I and |21, are preferably centrifugal pumps driven by electric motors. The main body of the upright chamber A may be reinforced by ribs formed by suitably shaping the metal. Other minor changes may be made in the structure herein disclosed without departing from the spirit and scope of the invention. It is intended by the terms of the `appended claims to cover all these alterations and modifications.

I claim:

1. An evaporator comprising a group of vertical tubes for carrying a liquid to be treated, means for conducting a heating medium into and out of heat exchange relation with said tubes, an inlet chamber in communication with the lower ends of said tubes, a cylindrical outlet chamber located at the upper ends of said tubes and having a discharge opening at one end and a horizontal axis, said tubes entering tangentially into said outlet chamber to direct the delivery of the heated liquid and vapor arising from the upper ends of said tubes Within said chamber into a centrifugal swirl about said axis, a downcomer passage leading from an opening in the bottom of said outlet chamber to said inlet chamber and thence to the lower ends of said tubes, said downcomer passage, inlet chamber, liquid treating tubes and outlet chamber providing a recirculating path, means for continuously supplying fresh liquid to said outlet chamber, flange-like baling means extending radially inward from the cylindrical wall of said outlet chamber, said bai-Fling means providing a central aperture through which vapor may be withdrawn from said outlet chamber and a marginal wall radially outside of said aperture for holding and guiding the partially concentrated liquid in a peripheral stream to said downcomer passage for recirculation over said recirculating path, and means Icomprising transverse openings through said bafing member near the bottom of said outlet chamber for continuously forwarding from said outlet chamber a quantity of the partially concentrated liquid constituting a small fraction of the total amount of liquid being recirculated.

2. In a sectional evaporator, the combination of an assembly of coplanar substantially duplicate units each including two sets of upright tubes arranged in heat exchange relation to each other, one set for heating and the other set for treating a liquid, each said set being composed of an intermediate corrugated sheet closed by plain parallel plates on opposite sides of said corrugated sheet, the plate completing the treating tubes being readily removable to facilitate cleaning the treating tubes, said latter plate being common to a plurality of said units, means for conducting a liquid to be treated into and out of said treating tubes, and means for conducting a heating medium into and out of said heating tubes.

. 3. An evaporator comprising a sheet having `vertically extending corrugations, vertical plates on opposite sides of said sheet contacting the ridges of said corrugations, one plate being movably mounted relatively to said sheet to facilitate 13 it being retracted from said sheet to expose for cleaning purposes the corrugation channels facing said movable plate, inlet and outlet means aligned respectively below and above and opening 'into the ends of said channels for effecting simultaneous unidirectional flow through the entire length of said channels of a fluid to be subjected to heat exchange while passing therethrough, and inlet and outlet means for the passage through the corrugation channels facing the other plate of another iiuicl for heat exchange with the aforesaid fluid.

4. An evaporator comprising a sheet having vertically extending corrugations, vertical plates on opposite sides of said sheet contacting the ridges of said corrugations, one plate being hingedly mounted relatively to said sheet to facilitate it being retracted from said sheet to expose for cleaning purposes the corrugation channels facing said hinged plate, inlet and outlet means aligned respectively below and above and opening into the ends of said channels for effecting simultaneous unidirectional 110W through the entire length of said channels of a iuid to be subjected to heat exchange while passing therethrough, and inlet and outlet means for the passage through the corrugation channels facing the other plate of another uid for heat exchange with the aforesaid fluid.

5. An evaporator comprising a sheet having vertically extending corrugations, vertical plates en opposite sides of said sheet contacting the ridges of said corrugations, one plate being movably mounted relatively to said sheet to facilitate it being retracted from said sheet to expose for cleaning purposes the corrugation channels facing said movable plate, inlet and outlet means for the passage through said channels facing said movable plate of a liquid to be subjected to heat exchange while passing therethrough, inlet and outlet means for the passage through the corrugation channels facing the other plate of heating uid for heat exchange with the aforesaid liquid, vapor separating means connected separately with the outlet means of separate groups of said first channels, means for returning to the inlet means of each said group the major portion of the unvaporized liquid discharged from each such group into said separating means, means for continuously and progressively forwardling a lesser portion of partially concentrated liquid received from a group carrying liquid of less concentration to a group carrying liquid of greater concentration, means for discharging vapor from the separating means, and means for discharging concentrated liquid from the group carrying liquid of greatest concentration.

6. An evaporator comprising groups of vertical tubes for carrying a liquid to be concentrated, means for supplying a heating medium for heating said tubes, a cylindrical vapor separator having a horizontal axis and so positioned and connected with said groups of tubes to receive tangentially thereinto from the outlet ends of said tubes heated liquid and vapor flowing therefrom, centrally apertured arcuate baille means for segregating as separate liquid bodies the liquid discharged from each said group, means for withdrawing vapor through said central apertures and from the separator, means icr returning from the separator to each group for recirculation therethrough the major portion of the liquid discharged from the same group, means for continuously and progressively forwarding a lesser portion of partially concentrated liquid received from a group carrying liquid of less concentration to a group carrying liquid of greater concentration, and means for discharging concentrated liquid from the group carrying liquid of greatest concentration.

7. An evaporator comprising groups of vertical tubes for carrying a liquid to be concentrated, means for supplying a heating medium for heating said tubes, a cylindrical vapor separator having a horizontal axis and so positioned and connected with said groups of tubes to receive tangentially thereinto from the upper ends of said tubes heated liquid and vapor flowing therefrom, centrally apertured arcuate baille means for segregating as separate liquid bodies the liquid discharged from each said group, means for withdrawing vapor through said central apertures and from the separator, means for returning from the separator to each group for recirculation therethrough the major portion of the liquid discharged from the same group, means for continuously and progressively forwarding a lesser portion of partially concentrated liquid received from a group carrying liquid of less concentration to a group carrying liquid of greater concentration, and means for discharging concentrated liquid from the group carrying liquid of greatest concentration.

JOSEPH A. CROSS.

REFERENCES CITED The following references are of record in the rile` of this patent:

UNITED STATES PATENTS Number Name Date 447,123 Theiser Feb. 24, 1891 482,340 Cooper Sept. 13, 1892 521,946 Cooper June 26, 1894 548,986 Hewitt Oct. 29, 1895 965,388 Kestner July 26, 1910 1,028,737 Kestner June 4, 1912 1,028,738 Kestner June 4, 1912 1,828,477 Seligman Oct. 20, 1931 1,883,379 Kermer Oct. 18, 1932 1,943,106 Burnham Jan. 9, 1934 1,966,181 Lowry July 10, 1934 2,147,993 Schiebe Feb. 21, 1939 2,150,860 Hughes Mar. 14, 1939 2,277,651 Steele Mar. 24, 1942 FOREIGN PATENTS Number Country Date 320,279 Great Britain Oct. 10, 1929 

